1. Field of the Invention
The present invention relates to a heat exchanger suitable for use in a condenser of a motor vehicle.
2. Description of the Related Art
FIG. 5 is a front view of a heat exchanger conventionally used for a motor vehicle air conditional condenser, and FIG. 6 is a schematic refrigerant system diagram of a motor vehicle air conditioner. In these figures, the same reference numerals are applied to the same elements of the heat exchanger of the apparatus incorporating the principles of the present invention.
As shown in FIG. 5, a heat exchanger 1 has a pair of header tubes 2 and 3 at both sides, a plurality of parallel heat exchange tubes 4 between these paired header tubes, and corrugated fins 5 interposed between the adjacent heat exchange tubes.
A refrigerant inlet coupling 6 is provided at an upper end of one of the header tubes 2 and 3, for example, the header tube 2. A partition plate 8 is inserted in the central portion of the header tube 2 to partition the interior of the header tube 2 into upper and lower portions. A refrigerant outlet coupling 7 is provided at a lower end of the partitioned lower portion of the header tube 2.
In the above mentioned heat exchanger 1, a high-pressure refrigerant compressed by a compressor (not shown) is applied to the header tube 2 through the refrigerant inlet coupling 6 of the heat exchanger 1 after going through a high-pressure refrigerant hose. The refrigerant enters the upper portion of the header tube 2 partitioned by the partition plate 8, goes therefrom through the parallel heat exchange tubes 4, and enters the header tube 3.
From the header 3, the refrigerant goes through the parallel heat exchange tubes 4 in the same manner, is sent under pressure to the lower portion of the header tube 2 partitioned by the partition plate 8, and discharged through the refrigerant outlet coupling 7. The refrigerant flowing in this manner has heat extracted by the corrugated fins 5 interposed between the adjacent heat exchange tubes in the process in which the refrigerant goes through the plurality of heat exchange tubes 4.
Generally, in the motor vehicle air conditioner, as shown in the schematic refrigerant system diagram of a motor vehicle air conditioner of FIG. 6, most of the functional components of the air conditioner are arranged in a motor vehicle engine compartment 101 subjected to a high temperature.
In FIG. 6, a refrigerant, which is sent under pressure from a compressor 103 that is mounted at the side of an engine 102 and driven by the engine 102 via a transmission belt, enters a condenser 1 through a high-pressure refrigerant hose 104.
The refrigerant, which gives up heat via the condenser 1, leaves the condenser 1 through a condenser refrigerant outlet 7, and is sent into a receiver 18 disposed in the engine compartment 101 through a refrigerant pipe 106 connecting the condenser refrigerant outlet 7 to a receiver inlet 181.
Then, the refrigerant leaves the receiver 18 through a receiver outlet 185, goes through a refrigerant pipe 108, and is subjected to adiabatic expansion and is cooled by an expansion valve 109 disposed in a motor vehicle compartment. After being heated by an evaporator 110, the refrigerant is sucked by the compressor 103 through a low-pressure refrigerant hose 111. Thus, the cycle of this air conditioner is completed. In FIG. 6, reference numerals 161 and 162 denote a radiator and a radiator panel, respectively.
FIG. 7 shows the receiver 18. In this figure, reference numeral 181 denotes a refrigerant inlet, 182 denotes a desiccant, 183 denotes a filter, 184 denotes a refrigerant suction pipe, and 185 denotes a refrigerant outlet.
FIGS. 8 and 9 show an example of a conventional heat exchanger integral with a receiver. FIG. 9 is an enlarged view of the principal portion of FIG. 8.
In FIGS. 8 and 9, a heat exchanger 1 comprises a pair of header tubes 2 and 3 at both sides, a plurality of parallel heat exchange tubes 4 arranged between these paired header tubes, corrugated fins 5 interposed between the adjacent heat exchange tubes, and a receiver body 18.
The upper end of a receiver body 18 is fixed to a receiver fixing bracket 10 mounted at the upper end or on the side surface at the upper position of the header tube 3 by means of fixing bolts 19. The lower end of receiver 18 is directly connected to a receiver connecting flange 11 mounted at the lower position of the header tube 3 by means of fixing bolts 20, so that the receiver body 18 is integral with the heat exchanger 1.
The header tube 2 has a refrigerant inlet 6 at the upper end and a refrigerant outlet 7 at the lower end. Partition plates 8a and 8b are inserted and fixed into the header tube 2 between the refrigerant inlet 6 and the refrigerant outlet 7 with a proper space to partition a refrigerant passage in the header tube 2 into three chambers A, C and F.
In the header tube 3, a partition plate 8c is inserted and fixed at a position corresponding to an approximately intermediate position of the space between the partition plates 8a and 8b in the header tube 2, so that a refrigerant passage in the header tube 3 is partitioned into chambers B and D. At the side of the chamber D of the header tube 3, refrigerant passage holes 12 and 13 are formed. The refrigerant passage holes 12 and 13 are partitioned in the header tube by a partition plate 9, so that a chamber E is formed under the partition plate 9 in the refrigerant passage of the header tube 3.
In the receiver connecting flange 11, which is connected to the header tube 3 by welding, a first refrigerant passage 14 communicates with the refrigerant passage hole 12 and a second refrigerant passage 15 communicates with the refrigerant passage hole 13. Also, the receiver connecting flange 11 has a flange surface through which the receiver body 18 is fixed by means of fixing bolts 20 via a receiver header 21. The header 21 is assembled and welded to the lower end of the receiver body 18 to form the receiver refrigerant inlet/outlet, and is threaded for the fixing bolts 20.
On the flange surface of the receiver connecting flange 11, a seal, such as an O-ring, is assembled to prevent leakage of refrigerant at the connection with the receiver header 21.
The receiver header 21 is formed with a receiver inlet passage 16 and a receiver outlet passage 17. When the receiver header 21 is connected to the receiver connecting flange 11 of the header tube 3, the receiver inlet passage 16 communicates with the first refrigerant passage 14 and the receiver outlet passage 17 communicates with the second refrigerant passage 15.
The chamber E, which is formed at the lower portion in the header tube 3, is connected to the chamber F. which is formed at the lowest portion in the header tube 2, by a plurality of parallel heat exchange tubes at this portion between the header tubes, and the chamber F is provided with the refrigerant outlet 7 of the heat exchanger 1.
The refrigerant entering the receiver 18 through the receiver inlet passage 16 goes through a refrigerant suction pipe 184, filter 183, and desiccant 182, and is conducted to the receiver outlet passage 17.
In the conventional receiver shown in FIGS. 7, 8, and 9, since it is necessary to make the refrigerant entering the receiver pass through the desiccant 182 to absorb water contained in the refrigerant. and it is also necessary to conduct the refrigerant at the receiver outlet, which is a liquid refrigerant accumulating at the lower part of the receiver, to a downstream expansion-valve (not shown), the refrigerant suction pipe 184 is required
For this reason, the receiver is large in diameter and size and the cost also increases.
An object of the present invention is to provide a heat exchanger with a receiver which has a small diameter and compact size without a liquid refrigerant suction pipe.